{- HetCATS/HasCASL/Merge.hs

$Id$

Authors: Christian Maeder

Year: 2002/2003

merging (parts of) local env

-}

module HasCASL.Merge where

import Common.Id

import HasCASL.As

import HasCASL.Le

import HasCASL.AsUtils

import HasCASL.Unify

import qualified Common.Lib.Map as Map

import Data.List

import Control.Monad.State

import Common.Result

-- for Logic.signature_union

instance Mergeable Env where

merge e1 e2 =

do cMap <- merge (classMap e1) $ classMap e2

tMap <- merge (typeMap e1) $ typeMap e2

let m = max (counter e1) $ counter e2

as <- mergeAssumps tMap m

(assumps e1) $ assumps e2

return $ Env cMap tMap as (envDiags e1 ++ envDiags e2) m

instance (Ord a, PosItem a, Mergeable b) => Mergeable (Map.Map a b) where

merge = mergeMap merge

mergeMap :: (Ord a, PosItem a) => (b -> b -> Result b)

-> Map.Map a b -> Map.Map a b -> Result (Map.Map a b)

mergeMap f m1 m2 = foldM ( \ m (k, v) ->

case k `Map.lookup` m of

Nothing -> return $ Map.insert k v m

Just w ->

let Result ds mu = f v w

ns = map ( \ d -> if diagPos d == nullPos

then d { diagPos = posOf [k] }

else d) ds

in case mu of

Nothing -> Result ns $ Nothing

Just u -> return $ Map.insert k u m)

m1 (Map.toList m2)

instance Mergeable a => Mergeable (Maybe a) where

merge m1 m2 = case m1 of

Nothing -> return m2

Just v1 -> case m2 of

Nothing -> return m1

Just v2 -> do v <- merge v1 v2

return $ Just v

instance Mergeable ClassInfo where

merge c1 c2 = do k <- merge (classKind c1) (classKind c2)

d <- merge (classDefn c1) (classDefn c2)

let s1 = superClasses c1

s2 = superClasses c2

if s1 == s2 then

return $ ClassInfo s1 k d

else fail "merge: non-equal super classes"

instance Mergeable Kind where

merge k1 k2 = if k1 == k2 then return k1

else fail "merge: non-equal kinds"

instance Mergeable Class where

merge c1@(Downset t1) (Downset t2) =

if t1 == t2 then return c1

else fail "merge: non-equal downset"

merge c1@(Intersection i1 _) (Intersection i2 _) =

if i1 == i2 then return c1

else fail "merge: non-equal intersection class"

merge _ _ = fail "merge: class"

mergeList :: Eq a => [a] -> [a] -> Result [a]

mergeList l1 l2 = return $ nub (l1 ++ l2)

instance Mergeable TypeInfo where

merge t1 t2 = do k <- merge (typeKind t1) $ typeKind t2

o <- mergeList (otherTypeKinds t1) $ otherTypeKinds t2

s <- mergeList (superTypes t1) $ superTypes t2

d <- merge (typeDefn t1) $ typeDefn t2

return $ TypeInfo k o s d

instance Mergeable TypeDefn where

merge d1 d2 =

case (d1, d2) of

(TypeVarDefn, TypeVarDefn) -> return d1

(TypeVarDefn, _) -> fail "merge: TypeVarDefn"

(_, TypeVarDefn) -> fail "merge: TypeVarDefn"

(NoTypeDefn, AliasTypeDefn _) -> fail "merge: AliasTypeDefn"

(AliasTypeDefn _, NoTypeDefn) -> fail "merge: AliasTypeDefn"

(NoTypeDefn, _) -> return d2

(_, NoTypeDefn) -> return d1

(_, _) -> if d1 == d2 then return d1 else

fail "merge: TypeDefn"

mergeAssumps :: TypeMap -> Int -> Assumps -> Assumps -> Result Assumps

mergeAssumps tm c = mergeMap (mergeOpInfos tm c)

mergeOpInfos :: TypeMap -> Int -> [OpInfo] -> [OpInfo] -> Result [OpInfo]

mergeOpInfos tm c l1 l2 =

foldM ( \ l o ->

let os = opType o

(es, us) = partition (\ e -> opType e == os) l

in if null es then

let bs = map (isUnifiable tm c os . opType) l

in if or bs then fail "illegal overloading"

else return (o:l)

else do r <- merge o $ head es

return (r : us)) l1 l2

instance Mergeable OpInfo where

merge o1 o2 =

do sc <- merge (opType o1) $ opType o2

as <- merge (opAttrs o1) $ opAttrs o2

d <- merge (opDefn o1) $ opDefn o2

return $ OpInfo sc as d

instance Mergeable TypeScheme where

merge s1 s2 = if s1 == s2 then return s1

else fail "unequal type schemes"

instance Mergeable [OpAttr] where

merge l1 l2 =

let binAttr a = case a of BinOpAttr _ _ -> True

_ -> False

(l1b, l1u) = partition binAttr l1

(l2b, l2u) = partition binAttr l2

lb = nubBy ( \ (BinOpAttr b1 _) (BinOpAttr b2 _) -> b1 == b2)

(l1b ++ l2b)

in if null l1u || null l2u then

return (l1u ++ l2u ++ lb)

else do u <- merge (head l1u) (head l2u)

return (u : lb)

instance Mergeable OpAttr where

merge (UnitOpAttr t1 p1) (UnitOpAttr t2 p2) =

if t1 == t2 then return $ UnitOpAttr t1 (p1 ++ p2)

else fail "unequal unit elements"

merge _ _ = fail "merge: OpAttr"

instance Mergeable OpDefn where

merge VarDefn VarDefn = return VarDefn

merge VarDefn _ = fail "merge: VarDefn"

merge _ VarDefn = fail "merge: VarDefn"

merge NoOpDefn d = return d

merge d NoOpDefn = return d

merge d@(ConstructData d1) (ConstructData d2) =

if d1 == d2 then return d else

fail "merge: constructor"

merge d@(SelectData c1 d1) (SelectData c2 d2) =

if d1 == d2 && sort c1 == sort c2 then return d else

fail "merge: selector"

merge d@(Definition d1) (Definition d2) =

if d1 == d2 then return d else

fail "merge: definition"

merge _ _ = fail "merge: OpDefn"